No abstract

Reflective groundcovers are management tools used in temperate regions where light can be a limiting factor to crop productivity. Although their effects on crops have been extensively studied, little is known about their ecological impacts on ground‐dwelling organisms. Theoretically, reflective groundcovers add structural complexity to the system and thus have the potential to create refuges for ground‐dwelling invertebrates. At the same time, groundcovers can create abiotic conditions underneath them that could potentially cause declines in the abundance and richness of ground‐dwelling invertebrates. During the summers of 2006 and 2007, white, woven, reflective polymer groundcovers were placed in two red raspberry (Rubus idaeus L.) cropping systems (organic and conventional) in south‐eastern New Brunswick to assess their effects on ground beetle richness, activity density and overall assemblage structure. A total of 8723 ground beetles belonging to 23 species were collected using pitfall traps. In contrast with the combined effects of cropping systems and sampling years, the use of a groundcover accounted for a small proportion of the variance in trap catches and caused little change in ground beetle richness, activity density and overall assemblage structure. Based on these results, we suggest that reflective groundcovers constitute promising management tools to increase light environment quality in row crops without being detrimental to ground beetle species that may contribute to pest suppression.

The use of rain shelters and reflective groundcovers has been shown to improve the economic and environmental sustainability of organic fruit crops prone to rain-driven epidemics of phytopathogens. Here, we tested whether these structures affect communities of epigean species. To this end, we studied rain shelters and white, synthetic reflective groundcovers placed in a red raspberry organic cropping system in New Brunswick, Canada, during two subsequent summers to assess their independent and combined effects on ground beetles (Coleoptera: Carabidae). 18,445 ground beetles belonging to 54 species were collected. Rain shelters and reflective groundcovers altered patterns of ground beetle species richness, activity density and functional diversity compared to the control, but to a limited extent. Thus, this study suggests that these structures, which have known benefits against phytopathogens, have no detrimental impact on epigean fauna.